Benzo[
c]phenanthridine alkaloids are distributed in Papaveraceous and Rutaceous plants and classified into two categories of fully aromatized bases and partially hydrogenated bases(B/C-
cis-11-hydroxyhexahydrobenzo[
c]phenanthridine skeleton). They have long history, in which the first isolation of chelidonine, a partially hydrogenated base, from Papaveraceous plant, was reported in 1839. Over a century later nitidine and fagaronine, O
4-type fully aromatized bases isolated from Rutaeceous plant, attracted much attention because of their antitumor activity. At present, a variety of pharmacological effects are recognized in natural and unnatural species. We, about forty years ago, started synthetic studies on fully aromatized bases focusing on structure-activity relationship of antitumor activity and succeeded in establishing widely-applicable synthetic methods. Recently the enantioselective synthesis of chelidonine was completed. Thus, in this review, we present our chemical history for the synthesis of benzo[
c]phenanthridine bases.
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